Elimination of DC-Link Voltage Ripple in PMSM Drives With a DC-Split-Capacitor Converter
Chao Zhang, Lei Xu, Xiaoyong Zhu, Yi Du, Li Quan
Abstract
This article presents an electrolytic capacitorless (ECL) motor drive based on a dc-split-capacitor converter. In order to decrease the dc-link voltage ripple of ECL motor drive, an active power decoupling circuit (APDC) with a dc-split-capacitor is proposed. The APDC is composed of two converters, among which the boost converter is named the main converter and the buck-boost converter is named the auxiliary converter. The output capacitors of the two converters are connected in series to increase the dc-link voltage, which expands the speed range of the internal permanent magnet synchronous motor. When there is voltage ripple on the capacitor of the main converter, the auxiliary converter will produce complementary voltage on another capacitor. In addition, an instantaneous current control strategy is proposed in the auxiliary converter to reduce the voltage ripple, while the conventional control strategy is applied in the main converter. The main converter can achieve unity power factor, and the auxiliary converter is used to suppress the dc-link voltage ripple. Experiments are conducted, and the results verify the feasibility and effectiveness of the APDC.